Question

What are X and Y respectively in the following set of reactions? 

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

\(Br_2\) / red P converts alcohols to alkyl bromides, and alpha bromination of aldehydes followed by hydrolysis leads to alpha-bromo hydroxy ketones.

Answer 1

The Correct Option is B

- In the first reaction, 1-butanol reacts with \(Br_2\) in the presence of red phosphorus to form 1-bromobutane by substitution of the -OH group. So, \(X =\) 1-bromobutane. 
- In the second reaction, butanal is first brominated at the alpha-position by \(Br_2\)/red P, forming an alpha-bromo aldehyde intermediate. Subsequent treatment with water leads to the formation of an alpha-bromo hydroxy compound, i.e., 3-bromo-1-hydroxybutanone. 
So, \(Y =\) 3-bromo-1-hydroxybutanone.